6004-2RS Sealed Deep Groove Ball Bearing – 20×42×12mm

£4.22

6004-2RS Sealed Deep Groove Ball Bearing – 20×42×12mm

Name: 6004-2RS Sealed Deep Groove Ball Bearing – 20×42×12mm
Brand: Pivot Bearings
SKU: BR-2RS-6004
Price: 4.22 GBP
Availability: InStock

£4.22

Taxes included. Shipping calculated at checkout.

In stock

6004-2RS Sealed Ball Bearing

Single-row deep groove ball bearing. Chrome steel, 2RS rubber seals.

Bore × OD × Width: 20×42×12mm
Type: 2RS rubber seals (2×)
Material: Chrome steel (GCr15)
Pack: Single bearing (1)

Ideal for: bikes, motors, pumps, fans, skateboards

Orders are dispatched within 1-2 working days from Mirfield, West Yorkshire. UK orders go by Royal Mail tracked delivery and usually arrive 3-5 working days after you order, from £3.99. International delivery is tracked and priced by weight; for most countries any import duty is shown at checkout, so there is nothing to pay on delivery. You'll get a tracking link by email when your order ships.

Delivery prices and times for every country

We offer a 30-day return policy on all unused items in their original packaging. To initiate a return, please contact us at info@pivotbearings.co.uk for approval and instructions. Unless the item is faulty or wrong, customers arrange and pay for return shipping; Pivot Bearings cannot be held responsible for return shipments that are lost or fail to deliver. Once your item is received and inspected, refunds are typically processed within 10 business days.

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6004-2RS Sealed Deep Groove Ball Bearing – 20×42×12mm FAQ 's

Frequently asked questions about the 6004-2RS Sealed Deep Groove Ball Bearing – 20×42×12mm

The "2RS" suffix stands for 2 Rubber Seals, meaning there is a seal on both sides of the bearing. These seals are typically made of synthetic rubber (like Nitrile) bonded to an internal steel reinforcing plate.

The rubber lips make direct contact with the bearing's inner ring, creating a tight physical barrier. This design serves two main purposes: it keeps the factory-installed grease locked inside and prevents destructive contaminants like dust, dirt, and moisture from getting in.

The choice between them comes down to a direct tradeoff between protection and speed:

2RS (Rubber Seals): These are contacting seals, meaning they physically touch the inner ring. This provides superior protection against fine dust, debris, and water splashes. However, the contact creates friction (seal drag), which generates heat and lowers the bearing's maximum allowable speed.
ZZ (Metal Shields): These are non-contacting shields, leaving a microscopic gap between the shield and the inner ring. Because there is no friction, the bearing can run at its maximum rated RPM. The downside is that they only protect against larger dust particles and cannot stop liquids or fine moisture.

Yes, they are classified as "greased for life." 2RS bearings arrive from the factory pre-filled with the exact amount of high-quality grease needed for their lifespan (usually occupying about 30% to 40% of the internal space).

You should never attempt to pry off the rubber seals to add more grease. Doing so will almost certainly bend the internal steel reinforcement of the seal, ruining its ability to snap back into place properly. This leads to grease leakage and premature failure. Run them until they wear out, then replace them.

While they are incredibly popular, they do have a few specific operating limits:

Temperature Constraints: Standard rubber seals degrade, harden, and crack if exposed to continuous temperatures above 110°C to 120°C. For extreme heat, you need specialized high-temperature seal materials like Viton.
Rotational Drag: Because the rubber lips rub against the inner ring, they cause a small amount of rotational resistance. If your application requires a component to spin completely freely with minimal effort, the friction from a 2RS seal will be too high.

Because deep groove bearings handle both radial loads and light axial loads, combined with the "set-it-and-forget-it" nature of the 2RS seals, they are used across countless industries:

Electric Motors and Power Tools: Keeping drywall dust or sawdust out of the motor internals.
Bicycles: Used in wheel hubs, bottom brackets, and headsets to withstand mud, rain, and washing.
Household Appliances: Washing machine drums, vacuum cleaner rollers, and ceiling fans.
Skateboards and Inline Skates: Shielding the internal balls from road grit and grime.